nfsd: move nfsd/auth.h into fs/nfsd

This header is used only in a few places in fs/nfsd, so there seems to
be little point to having it in include/. (Thanks to Robert Day for
pointing this out.)

Cc: Robert P. J. Day <[e-mail]>
Acked-by: NeilBrown <[e-mail]>
Signed-off-by: J. Bruce Fields <[e-mail]>

fs/nfsd/nfs3xdr.c

···
 #include <linux/sunrpc/svc.h>
 #include <linux/nfsd/nfsd.h>
 #include <linux/nfsd/xdr3.h>
+#include "auth.h"
 
 #define NFSDDBG_FACILITY		NFSDDBG_XDR
 

fs/nfsd/nfsfh.c

···
 #include <linux/sunrpc/svc.h>
 #include <linux/sunrpc/svcauth_gss.h>
 #include <linux/nfsd/nfsd.h>
+#include "auth.h"
 
 #define NFSDDBG_FACILITY		NFSDDBG_FH
 

fs/nfsd/nfsxdr.c

···
 #include <linux/nfsd/nfsd.h>
 #include <linux/nfsd/xdr.h>
 #include <linux/mm.h>
+#include "auth.h"
 
 #define NFSDDBG_FACILITY		NFSDDBG_XDR
 

include/linux/nfsd/Kbuild

···
 unifdef-y += syscall.h
 unifdef-y += nfsfh.h
 unifdef-y += debug.h
-unifdef-y += auth.h

include/linux/nfsd/nfsd.h

···
 #include <linux/nfsd/debug.h>
 #include <linux/nfsd/nfsfh.h>
 #include <linux/nfsd/export.h>
-#include <linux/nfsd/auth.h>
 #include <linux/nfsd/stats.h>
 /*
  * nfsd version

include/linux/nfsd/syscall.h

···
 #include <linux/nfsd/const.h>
 #include <linux/nfsd/export.h>
 #include <linux/nfsd/nfsfh.h>
-#include <linux/nfsd/auth.h>
 
 /*
  * Version of the syscall interface